[PATCH 4.9 093/104] ASoC: wm_adsp: Return an error on write to a disabled volatile control

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>


[ Upstream commit 67430a39ca7a6af28aade5acb92d43ee257c1014 ]

Volatile controls should only be accessed when the firmware is active,
currently however writes to these controls will succeed, but the data
will be lost, if the firmware is powered down. Update this behaviour such
that an error is returned the same as it is for reads.

Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 sound/soc/codecs/wm_adsp.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -789,7 +789,10 @@ static int wm_coeff_put(struct snd_kcont
 
 	mutex_lock(&ctl->dsp->pwr_lock);
 
-	memcpy(ctl->cache, p, ctl->len);
+	if (ctl->flags & WMFW_CTL_FLAG_VOLATILE)
+		ret = -EPERM;
+	else
+		memcpy(ctl->cache, p, ctl->len);
 
 	ctl->set = 1;
 	if (ctl->enabled && ctl->dsp->running)
@@ -816,6 +819,8 @@ static int wm_coeff_tlv_put(struct snd_k
 		ctl->set = 1;
 		if (ctl->enabled && ctl->dsp->running)
 			ret = wm_coeff_write_control(ctl, ctl->cache, size);
+		else if (ctl->flags & WMFW_CTL_FLAG_VOLATILE)
+			ret = -EPERM;
 	}
 
 	mutex_unlock(&ctl->dsp->pwr_lock);